1. Field of the Invention
The present invention relates to a conductor connection method using a ring-shaped caulking member, a conductor connection structure, and a solar cell module to which the conductor connection structure is applied.
2. Related Background Art
A number of methods are known as methods for coupling a conductor with a plurality of other conductors. An example thereof is soldering. Conductors can be readily coupled to each other by soldering. In the case of electrical connection made by soldering, however, amounts of solder applied vary depending upon workers and this results in variations in contact resistance between conductors, which can lead to degradation of reliability. When the soldering work is done outdoors in the cold winter season, a considerable time is necessary for the conductors to reach the melting temperature of the solder.
Another example of connection is a method of coupling a conductor with a plurality of other conductors by welding, but the apparatus for welding is large in size and hard to move and carry. Therefore, this method is not suitable for outdoor works.
For this reason, an electrical connection member called a ring sleeve is frequently used for outdoor, electrical connection works. The ring sleeve is a ring-shaped caulking member, through which a plurality of conductors are passed and crimping (or crimped connection) is effected to establish electrical conduction between the conductors.
The following methods are applied to the coupling between one conductor and a plurality of other conductors with the use of the ring sleeve.
(Method 1)
As shown in FIG. 1, a conductor 10 is cut at positions where conductors 11 are to be coupled thereto and each pair of two cut ends of the conductor 10 are electrically connected to a conductor 11 with a ring sleeve 12.
(Method 2)
As shown in FIG. 2, a conductor 20 is preliminarily threaded through ring sleeves 22 in the same number as the number of conductors 21 to be coupled. The ring sleeves are moved to the positions where the conductors 21 are to be coupled, and thereafter the conductors 21 are passed through the corresponding ring sleeves 22 and crimping is carried out to establish electrical connection.
However, since the method 1 necessitates the cutting work of the conductor 10 at the positions where the conductors 11 are to be coupled thereto, the number of cut portions of the conductor 10 increases depending upon the number of conductors 11 to be coupled. Since the increase in the cut portions of the conductor also increases the total contact resistance between the conductors, power loss becomes significant. In addition, the conductor cut at a plurality of positions and connected by the ring sleeves is inferior in reliability to a single conductor. Further, the method 1 requires the work of cutting the conductor 10 at the coupling positions of the conductors 11, and is thus disadvantageous in that the cutting work takes some time and the number of parts increases.
On the other hand, the method 2 requires the preparatory work of threading the conductor 20 through the ring sleeves in the same number as the number of conductors 21 to be coupled, and thus does not allow a new conductor to be coupled between conductors having already been coupled. Since the ring sleeves correspond to the respective conductors 21, there is a high possibility that a conductor 21 is incorrectly coupled using another ring sleeve than its corresponding ring sleeve during the work. Further, where there is no space between a conductor and a mount body to which the conductor is fixed, the crimping work of the ring sleeve must be carried out by forcing a crimping tool into between the conductor and the mount body, so that undue stress may be exerted on the conductor.
The present invention has been accomplished in order to solve the above problems and an object of the invention is to provide a conductor connection method and a conductor connection structure permitting one conductor to be readily coupled to one or more other conductors with the use of a ring sleeve (ring-shaped caulking member), and a solar cell module to which the conductor connection structure is applied.
For achieving the object, a preferred embodiment of the present invention is a method of connecting conductors, comprising the steps of bending a portion of a first conductor to form a facing portion where two regions face each other, inserting the facing portion and a second conductor into a ring-shaped caulking member, and effecting crimping.
Another preferred embodiment of the present invention is a method of connecting conductors, which comprises, in sequence, the steps of bending a first conductor to form a facing portion where two regions face each other; inserting the facing portion into a ring-shaped caulking member; bending a head of the facing portion; inserting a second conductor into the ring-shaped caulking member; crimping the ring-shaped caulking member; and turning a crimped portion down onto an installation surface.
Another preferred embodiment of the present invention is a conductor connection structure comprising a first conductor having a bent portion where two regions face each other to form a facing portion; a second conductor; and a ring-shaped caulking member crimping the facing portion of the first conductor and the second conductor.
Another preferred embodiment of the present invention is a solar cell module comprising a plurality of photovoltaic elements, and an electrical connection member for electrically connecting the plurality of photovoltaic elements, wherein a facing portion having two regions faced each other formed by bending a portion of the electrical connection member, and an electrode member of the photovoltaic element are crimped with a ring-shaped caulking member.
The conductor connection methods, the conductor connection structure, and the solar cell module as described above obviate the need for cutting the first conductor at the position where the second conductor is to be coupled, which can prevent the degradation of reliability of the connection part. They can obviate the need for the cutting work of the first conductor or the work of preliminarily threading the first conductor through the ring-shaped caulking members in the same number as the second conductors to be coupled thereto, which enhances workability. Since there is no need for the work of preliminarily threading the first conductor through the ring-shaped caulking members, another conductor may also be added afterward in such a manner that the additional conductor is connected to the first conductor with a ring-shaped caulking member.
Other features and other advantageous effects of the present invention will be detailed hereinafter with reference to the drawings.